Is there a way to tell nuGet to install a file, into a project, only if the file is not already in the project?

Is there a way to configure a nuGet package so that a file is installed, inside a project, only if it does not already exist in the project?

Specifically, my nuGet package contains a custom config file. Once installed, the user will make modifications to the file. The problem is that the config file gets replaced when the user installs a new version of my nuGet package -- thus, losing their changes.
I want to prevent this.